Help meeeee

Please help!!!!
I woke up this morning at 137.4 pounds, Later I ate a small amount of rice, and now I'm at 139.0 pounds!!!! I got several weights from the scale: 139.6 139.4 139.2 138.8 and 138.6. A few minutes ago i re-weighed and my weight was at 138.6 or 138.8. its probably still going up and down. How is that possible to gain that much weight? I ate the rice fast and I checked the calories (200 in a cup) and I only had about a cup size. I feel so bad. It was great that I got down to 137.4, but a goal was set that by tomorrow my weight has to be 138.6 pounds. I have to weigh that much by tomorrow morning or night. I feel like its my fault. I think my overall calorie consumption for today was 400-600. All that hard work, gone. BTW, sorry if I sound like a drama queen. I'm just upset and really needed to weigh 138 pounds by tomorrow.

Can someone tell me if this is fat or not and if its going to go down by tomorrow?
And, if there are ways I can make it go down by tomorrow.